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From: Arjan van de Ven <arjan@infradead.org>
To: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Len Brown <lenb@kernel.org>,
	x86@kernel.org, linux-pm@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org, Len Brown <len.brown@intel.com>
Subject: Re: [PATCH 8/8] intel_idle: create a native cpuidle driver for select intel processors
Date: Thu, 27 May 2010 07:22:07 -0700	[thread overview]
Message-ID: <20100527072207.2e783b1e@infradead.org> (raw)
In-Reply-To: <87ljb5l9d5.fsf@deeprootsystems.com>

On Thu, 27 May 2010 07:14:46 -0700
Kevin Hilman <khilman@deeprootsystems.com> wrote:

> Len Brown <lenb@kernel.org> writes:
> 
> > From: Len Brown <len.brown@intel.com>
> >
> > This EXPERIMENTAL driver supersedes acpi_idle
> > on modern Intel processors. (Nehalem and Atom Processors).
> >
> > For CONFIG_INTEL_IDLE=y, intel_idle probes before acpi_idle,
> > no matter if CONFIG_ACPI_PROCESSOR=y or =m.
> >
> > Boot with "intel_idle.max_cstate=0" to disable the driver
> > and to fall back on ACPI.
> >
> > CONFIG_INTEL_IDLE=m is not recommended unless the system
> > has a method to guarantee intel_idle loads before ACPI's
> > processor_idle.
> >
> > This driver does not yet know about cpu online/offline
> > and thus will not yet play well with cpu-hotplug.
> >
> > Signed-off-by: Len Brown <len.brown@intel.com>
> > ---
> >  MAINTAINERS                     |    7 +
> >  drivers/Makefile                |    2 +-
> >  drivers/acpi/processor_driver.c |    6 +-
> >  drivers/idle/Kconfig            |   11 +
> >  drivers/idle/Makefile           |    1 +
> >  drivers/idle/intel_idle.c       |  446
> > +++++++++++++++++++++++++++++++++++++++
> 
> Any reason this arch-specific driver needs to be in drivers/idle
> instead of under a platform specific dir like arch/x86?
> 
> On embedded SoCs that have never had ACPI, we have our
> platform-specific CPUidle drivers in with the rest of our platform
> specific code.
> 

it's really inconvenient to have such drivers hidden in the
architecture code; it's much more convenient for cpuidle developers
if they're all in one place.
Think of it this way: you're not putting the NIC driver for your SOC in
a architecture directory either...


-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org

  reply	other threads:[~2010-05-27 14:19 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-05-27  2:42 idle-test patches queued for upstream Len Brown
2010-05-27  2:42 ` [PATCH 1/8] cpuidle: fail to register if !CONFIG_CPU_IDLE Len Brown
2010-05-27  2:42   ` [PATCH 2/8] cpuidle: add cpuidle_unregister_driver() error check Len Brown
2010-05-27  3:14     ` Andrew Morton
2010-05-27  5:11       ` [PATCH-v2 " Len Brown
2010-05-27  5:13         ` Andrew Morton
2010-05-27  2:42   ` [PATCH 3/8] cpuidle: make cpuidle_curr_driver static Len Brown
2010-05-27  5:27     ` [PATCH-v2 " Len Brown
2010-05-27 18:40       ` Luck, Tony
2010-05-27 23:30         ` Len Brown
2010-05-27  2:42   ` [PATCH 4/8] ACPI: allow a native cpuidle driver to displace ACPI Len Brown
2010-05-27  2:42   ` [PATCH 5/8] sched: clarify commment for TS_POLLING Len Brown
2010-05-27  5:53     ` [PATCH-v2 " Len Brown
2010-05-27  2:42   ` [PATCH 6/8] acpi_pad: uses MONITOR/MWAIT, so it doesn't need to clear TS_POLLING Len Brown
2010-05-27  2:42   ` [PATCH 7/8] ACPI: acpi_idle: touch TS_POLLING only in the non-MWAIT case Len Brown
2010-05-27  2:42   ` [PATCH 8/8] intel_idle: create a native cpuidle driver for select intel processors Len Brown
2010-05-27  3:44     ` Andrew Morton
2010-05-28  3:57       ` Len Brown
2010-05-30  9:20         ` Andi Kleen
2010-05-27  8:53     ` [linux-pm] " Thomas Renninger
2010-05-28  1:44       ` Len Brown
2010-05-28  7:46         ` Thomas Renninger
2010-05-28 17:38           ` Len Brown
2010-05-29  4:17         ` Thomas Renninger
2010-05-27 14:14     ` Kevin Hilman
2010-05-27 14:22       ` Arjan van de Ven [this message]
2010-05-27 14:36         ` Kevin Hilman
2010-05-28  0:22           ` Len Brown
2010-05-28 17:28             ` Kevin Hilman
2010-05-27 14:51         ` [linux-pm] " Igor Stoppa
2010-05-28  3:14           ` Arjan van de Ven
2010-05-28 17:27             ` Kevin Hilman
2010-05-29  0:38               ` Arjan van de Ven
2010-05-28  2:32     ` Chase Douglas
2010-05-28  4:16       ` Len Brown
2010-05-28 15:09         ` Chase Douglas
2010-05-28 17:43           ` Len Brown
2010-05-28 19:51             ` Chase Douglas
2010-05-28 20:14               ` Chase Douglas
2010-05-27  5:25   ` (No subject header) Milton Miller
2010-05-27  5:47     ` Len Brown
2010-05-27  8:45 ` [linux-pm] idle-test patches queued for upstream Thomas Renninger
2010-05-28  0:59   ` Len Brown
2010-05-28  8:07     ` Thomas Renninger
2010-05-28 17:42       ` Len Brown
2010-06-16  7:53     ` Pavel Machek

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